jBPM

jBPM (Java Business Process Model) is an open-source workflow engine written in Java that can execute business processes described in BPMN 2.0 (or its own process definition language jPDL in earlier versions). jBPM is a toolkit for building business applications to help automate business processes and decisions. It's sponsored by Red Hat, part of the JBoss community and closely related to the Drools and OptaPlanner projects in the KIE group. It is released under the ASL (or LGPL in earlier versions) by the JBoss company.